<template>
	<view>

		<view class="scroll-view-container">
			<!-- 左侧的滑动区域 -->
			<scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh+'px'}">
				<block v-for="(item, i) in cateList" :key="i">
					<view :class="['left-scroll-view-item', i === active ? 'active' : '']" @click="activeChange(i)">
						{{item.cat_name}}
					</view>
				</block>
			</scroll-view>
			<!-- 右侧的滑动区域 -->
			<scroll-view scroll-y="true" :style="{height: wh +'px'}" :scroll-top="scrollTop">
				<!-- 当前一级分类下的二级分类列表 -->
				<view class="cate-lv3-list">
					<!-- 二级分类的item项 -->
					<view class="cate-lv3-item" v-for="(item3, i3) in cateLevel2" :key="i3"
						@click="gotoGoodsList(item3)">
						<!-- 三级分类的图片 -->
						<image src="/static/cate.png" mode="widthFix" />
						<!-- 三级分类的文本 -->
						<text>{{item3.cat_name}}</text>
					</view>
				</view>
			</scroll-view>
		</view>
	</view>
</template>

<script>
	export default {
		data() {
			return {
				//当前设备可用的高度
				wh: 0,
				cateList: [{
						cat_name: "海外购",
						children: [{
							cat_name: "海信"
						}, {
							cat_name: "TCL"
						}]
					},
					{
						cat_name: "手机相机",
						children: [{
							cat_name: "华为"
						}, {
							cat_name: "小米"
						}]
					},
					{
						cat_name: "电脑办公"
					},
					{
						cat_name: "厨卫电器"
					}
				],
				active: 0,
				//二级分类的列表
				cateLevel2: [],
				scrollTop: 0
			};
		},
		onLoad() {
			const sysInfo = uni.getSystemInfoSync()
			this.wh = sysInfo.windowHeight - 50

			this.getCateList()
			if (this.cateList.length > 0)
				this.cateLevel2 = this.cateList[0].children;
		},
		methods: {
			//获取分类列表的数据
			async getCateList() {

			},
			activeChange(i) {
				this.active = i

				//重新为二级分类赋值
				this.cateLevel2 = this.cateList[i].children

				this.scrollTop = this.scrollTop === 0 ? 1 : 0
			},
			//跳转到商品列表页面
			gotoGoodsList(item) {
				uni.navigateTo({
					url: '/subpkg/goods_list/goods_list?cid=' + item.cat_id
				})
			},
			gotoSearch() {
				uni.navigateTo({
					url: '/subpkg/search/search'
				})
			}
		}
	}
</script>

<style lang="scss">
	.scroll-view-container {
		display: flex;

		.left-scroll-view {
			width: 120px;

			.left-scroll-view-item {
				background-color: #F7F7F7;
				line-height: 60px;
				text-align: center;
				font-size: 12px;

				&.active {
					background-color: #FFFFFF;
					position: relative;

					&::before {
						content: ' ';
						display: block;
						width: 3px;
						height: 30px;
						background-color: #C00000;
						position: absolute;
						top: 50%;
						left: 0;
						transform: translateY(-50%);
					}
				}
			}
		}

		.cate-lv2-title {
			font-size: 12px;
			font-weight: bold;
			text-align: center;
			padding: 15px 0;
		}

		.cate-lv3-list {
			display: flex;
			flex-wrap: wrap;

			.cate-lv3-item {
				width: 33.33%;
				display: flex;
				flex-direction: column;
				justify-content: center;
				align-items: center;
				margin-bottom: 10px;

				image {
					width: 60px;
					height: 60px;
				}

				text {
					font-size: 12px;
				}
			}
		}
	}
</style>
